New York City lawmakers sharply criticized the city’s correction commissioner on Wednesday, raising pointed questions about his ability to curb pervasive violence against inmates at Rikers Island.

At a hearing, members of the City Council challenged the commissioner, Joseph Ponte, over his decision to promote a senior uniformed correction official who had been involved in reporting distorted data on violence three years ago. In May, Mr. Ponte appointed the official, William Clemons, as chief of department, the top uniformed position, despite a recommendation against it by the city’s Department of Investigation.

“I don’t know if that sends a positive and affirming message to us that serious changes will continue,” said Melissa Mark-Viverito, the City Council speaker, calling Mr. Clemons “clearly incompetent.”

Ms. Mark-Viverito cited an article that appeared in The New York Times last month. It described an internal Correction Department audit that found Mr. Clemons had underreported inmate fights and recommended that he be demoted.

When pressed later, Mr. Ponte said he stood by his decision.

“I’m not saying that’s fine,” he said, “but that happened a long time ago.”

Since taking office in April, Mr. Ponte has generally escaped serious criticism about the problems at Rikers. A seasoned correction official with a reputation as a reformer, he was appointed by Mayor Bill de Blasio with a mandate to rein in brutality and corruption. But he has been under pressure to produce results, amid persistent scrutiny by elected officials, the news media and federal authorities.

In August, the United States attorney’s office in Manhattan released a report about a “deep-seated culture of violence” against adolescent inmates at Rikers Island; the report warned that the city would be sued if the problems were not addressed within a 49-day period that ended in late September.

At the hearing, which was called to discuss the report, Mr. Ponte assured lawmakers that progress had been made in negotiations, but that it would take several months to work out the details. “There’s nothing in that report I disagree with,” he said.

City officials have devoted varying levels of attention to inmate violence at Rikers over the years, but the hearing on Wednesday was the first time in recent memory that they confronted the issue of brutality by guards. In June, it was barely mentioned during a four-hour hearing on jail violence. On Wednesday, Councilwoman Elizabeth Crowley, who represents part of Queens and is the chairwoman of the Fire and Criminal Justice Services Committee, signaled in her opening remarks that this time would be different.

“This oversight committee needs assurance that inmates are safe, that there is no tolerance for abuse of power and that officers are held accountable,” she said.

Mr. Ponte described several changes, including reviewing every use-of-force case by guards at the juvenile jail. He said the department had added five investigators at the jail and improved the inmate-to-guard ratio to 15 to 1 from 33 to 1.

There has been progress on ending solitary confinement, by the end of the year, for 16- and 17-year-olds, he said. In October, the average daily population in solitary confinement was 20, down from 30 two months earlier, Mr. Ponte said.

Still, Ms. Mark-Viverito noted that on a recent visit, she had met a teenager who had been sentenced to 375 days in solitary confinement. Another council member, Fernando Cabrera, criticized the department for not having an adolescent psychiatrist on staff.

A consensus seemed to be forming among the lawmakers that Rikers Island was no place for adolescents. Several pressed the commissioner on the possibility of moving them to another jail, possibly in Brooklyn or Queens.

“Any plan of action to reform the city’s Department of Correction must begin with removing all of the 16- and 17-year-old inmates off Rikers Island,” Ms. Crowley said. “Putting teens in adult jails only makes them more likely to have a lifetime of contact with the criminal justice system.”

Mr. Ponte said he was not opposed to moving the adolescents, but added that current facilities in Brooklyn and Queens were too small and too poorly arranged to provide the kind of therapeutic programing now being put into place at Rikers Island.

“There is no quick, easy solution,” he said. “But we will continue to explore other buildings and other opportunities.”

Lawmakers repeatedly questioned Mr. Ponte’s decision to promote Mr. Clemons. The internal Correction Department audit described by The Times found that while Mr. Clemons was warden of the jail for adolescents in 2011, hundreds of inmate fights were not included in official statistics. Although the audit said there was insufficient evidence to prove intentional manipulation, it described Mr. Clemons and his deputy as incompetent.

Mr. Clemons was never punished; he was promoted several times.

“Do you worry about what kind of message that may send to correction officers if the leaders of the institutions themselves can alter reports and get away with it?” Councilman Daniel Dromm asked.

“I don’t share your same concern,” Mr. Ponte responded.

Ms. Crowley asked why Mr. Clemons, who typically accompanies the commissioner during such hearings, was absent. He “did not have the backbone” to show up, she said.

“How could you let the chief of department not be here to answer questions?” she asked.

Mr. Ponte responded that Chief Clemons was on vacation, adding: “It is what it is.”

A version of this article appears in print on , on Page A27 of the New York edition with the headline: Head of Jails Is Criticized on Violence at Rikers. Order Reprints | Today’s Paper | Subscribe